Customized applications for mobile networks enhanced Logic (CAMEL), is designed to work on either a global system for mobile communications (GSM) core network or universal mobile telecommunications system (UMTS) network. CAMEL allows an operator to define services over and above standard GSM services/UMTS services. CAMEL architecture is based on Intelligent Network (IN) standards, and uses the CAMEL application part (CAP) protocol.
Many services can be created using CAMEL, and it is particularly effective in allowing these services to be offered when a subscriber is roaming, like for instance no-prefix dialing (the number the user dials is the same no matter the country where the call is placed) or seamless MMS message access from abroad.
CAMEL has been specified in 4 phase. phase1 and phase2 support adding IN services to a GSM network. CAMEL phase 1 provides basic call control capabilities such as call forwarding and basic virtual private network (VPN). CAMEL phase2 provides more advanced capabilities (both call control and non-call control related) such as on-line charging (call-control) and unstructured supplementary service data (USSD) control (non-call control). Phases3 and 4 support adding services to a unstructured supplementary service data (UMTS) network. All 4 phases can be used in either a GSM or a UMTS network.
In a normal and traditional scenario where there are multiple operators who want that their subscribers should get the mobile services in the other networks (partner network), they need to undergo a roaming agreement amongst them in order to establish smooth rollout of roaming services to their subscribers in the partner network. Since there are so many operators in the world and subscriber of any operator can move to any operator in the world, each operator has a need to undergo for such an agreement with almost every other operator in the world. This process is a very lengthy process and creates a mesh of agreements among all these operators. For a prepaid subscriber, over and above these agreements for roaming, there is a requirement of undergoing CAMEL test cases with each of the operators. Due to lots of incompatibility in the CAMEL version/phases running with these operators, this may result in a mesh.
Thus, a need exists for a centralized approach to provide CAMEL roaming services.